Silencer



Feb. 14, 1939. F. E. DER EMER S ILENCE'R Filed Nov. 5, 1936 3 Sheets-Sheet 1 BY 9. OR. AW fq rmw.

5 11 2 0 t 7 W M W 2 m R. h T E T. 1 T A R 6 E w M ma Ems, 13 E DEW .IN E R Y F B Feb. 14, 1939.

Feb. 14, 1939. F. E. DEREMER 2,147,015

SILENCER Filed Nov. 5, 1956 3 Sheets-Sheet 3 EQE Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE 9 Claims.

This application relates to silencers particularly for use with internal combustion engines.

The silencer herein disclosed is characterized by the fact that though it comprises an outer casing, two intermediate shells, and two inner tubes, all arranged to provide a retroverted flow ior the gases passing through the silencer, the parts are properly supported within the outer casing without requiring the use of intermediate headers. The elimination of these headers enhances the economy and the efiiciency of the silencer inasmuch as it reduces the number of parts and also permits the utilization of the entire volume of the outer casing for tuning without part of that volume being cut off by the use of inner heads.

The silencer is also characterized by the fact that one of the intermediate shells is apertured just ahead of the terminal of the inner tube therein with the result that the flow of gas through such inner tube causes an aspirator effect within the intermediate shell, resulting in gases being drawn from the outer casing into the intermediate shell and thus cooling the incoming exhaust gases. To enhance this action the intermediate shell is provided with an inwardly projecting bead adjacent the terminal of the inner tube and this bead gives a Venturi action to the silencer. The bead is formed by rolling-in the wall of the intermediate shell adjacent the terminal of the inner tube therein.

*The rolled-in bead is so constructed that it presents no sharp edges to the flow of gases with the result that there is no turbulence; similar beads are used to join the inner tube to the intermediate shell and to reinforce the intermediate shell at points remote from the terminal of the inner tube. These beads also permit expansion of the intermediate shell, acting as bellows.

The aspirator action above described, which is produced in part by the presence of the bead adjacent the terminal of the inner shell is partly responsible for eliminating the inner headers as above mentioned. The use of such headers has previously been considered necessary in silencers of this general type. Because of the aspirator efiect utilized here, it is possible to eliminate such headers with consequent advantageous results.

In cases where the intermediate shells are juxtaposed, the beads formed inwardly from the inner shells define grooves on the outsides of the intermediate shells which create passages between opposed volumes of the outer shell, and

(c1. 1s1-5s) the presence of these passages enhances the silencer action as well as increasing the volume of the outer casing without increasing the diameter of the outer casing and also increase the resonating range of the outer casing by providing irregularities in the contour of the effective volume of the outer casing.

For an understanding of the silencer herein shown, reference should be had to the appended drawings, in which Fig. 1 is a cut-away longitudinal section of the silencer;

Figs. 2 and 3 are transverse sections on lines 2-2 and 33 of Fig. 1;

Fig. 4 is a cut-away elevation of the silencer; and

Fig. 5 is a diagrammatic view.

Fig. 6 is a longitudinal section on line 6-5, Fig. 7, of another form of silencer.

Fig. '7 is a transverse section thereof.

Referring to the drawings it will be seen that the silencer therein shown comprises an outer casing I closed at its ends by inlet and outlet headers l ll2 having apertures through which pass inlet and outlet inner tubes [4-45, these being telescoped within inlet and outlet intermediate shells |6--l1 arranged as shown, to divide the outer casing into opposed volumes l8 and I9.

Gases entering the silencer through the inlet tube l4 course therethrough until they reach the end of the intermediate shell is, whereupon they discharge into the outer casing at the outlet end, and these gases then course through the outer casing to the inlet end thereof from whence they enter the intermediate shell I! and the outlet tube l to discharge from the free end of the latter.

The inner tubes are perforated as indicated at 2| to provide drain holes and also to communicate the interior of the inner tubes with the space surrounding them within the intermediate shells and such space is divided by beads 22 rolled inwardly from the intermediate shells into silencer chambers; the intermediate shells are also provided with drain holes, not shown.

The intermediate shell H5, at a zone adjacent the outlet end of the inner tube I4, is provided with holes 23 which communicate the interior of the intermediate shell with the space within the outer casing and through these holes gases from the outer casing are drawn into the intermediate shell l6 by the aspirator effect produced by the coursing of gases at high velocity through the inner tube l4 and the discharge of these gases from the terminal of the inner tube l4 past the Venturi bead 24 adjacent such terminal.

It will be observed that the beads formed in the inner shells are not all of the same diameter. The beads which engage the inner tubes are proportioned to extend to the inner tubes; the bead 2 which produces the Venturi effect is of slightly less depth than the inner tube engaging beads, and the bead 26 spaced further along the path of flow of the gases from the bead 24 is of even less depth than such bead. Thus the beads are of gradually expanding diameters along the flow of gases to compensate for the increased volume of gases brought into the intermediate shell [6 by the aspirator effect.

It will also be observed that the grooves provided by the beads 22 provide passage ways between opposed volumes Hll9 of the outer casing, and thus permit by-passing between these volumes to enhance the silencer action, and these grooves also increase the volume of the outer casing above what would be the case if there were no such grooves, without requiring an increase in the diameter oi the casing, and also increase the resonating range of the outer casing by providing irregularities in the contour of the effective volume of the outer casing.

It will also be observed that the inner shells and tubes may be arranged 180 apart, as in Figs. 1-5, or 120 apart, as in Figs. 6 and 7, as desired.

Now having described the silencer hereof, reference will be had to the claims which follow for a determination of the protection sought by this application.

I claim:

1. A silencer comprising an outer casing, headers closing the ends thereof, intermediate shells disposed in side by side relation therein, and in. ner tubes within the intermediate shells, one of the intermediate shells having beads projecting inwardly therefrom and extending to the inner tube therein, some of the beads being in a part of the intermediate shell in which there is no inner tube.

2. A silencer comprising an outer casing, an intermediate shell therein, and an inner tube within the intermediate shell, the latter having apertures between the inlet and outlet ends of the inner tube, and having an inwardly projecting formation between the outlet end of the in ner tube and the outlet end of the intermediate shell, and adjacent the outlet end of the inner tube.

3. A silencer comprising an outer casing, an intermediate shell therein, and an inner tube within the intermediate shell, the latter having apertures between the inlet and outlet ends of the inner tube, and having an inwardly projecting bead between the outlet end of the inner tube and the outlet end of the intermediate shell, and adjacent the outlet end of the inner tube.

4. A silencer comprising an outer casing, two shells therewithin disposed adjacent each other and side by side and dividing the casing into opposed portions, and beads projecting inwardly from the shells to define grooves therein providing passageways between the opposed portions of the casing.

5. A silencer comprising an outer casing, two shells therewithin disposed adjacent each other and side by side and dividing the casing into opposed portions, and beads projecting inwardly from the shells to define grooves therein providing passageways between the opposed portions of the casing, and tubes in the shells, the beads spanning the space between the tubes and the shells.

6. A silencer comprising an outer casing, an intermediate shell therein, and an inner tube within the intermediate shell, the latter having apertures between the inlet and outlet ends of the inner tube, and having an inwardly projecting bead between the outlet end of the inner tube and the outlet end or the intermediate shell, and adjacent the outlet end of the inner tube, and beads projecting inwardly from the intermediate shell to and engaging the inner tube.

7. A silencer comprising an outer casing, headers closing the ends thereof, intermediate shells disposed in side by side relation therein, inner tubes within the intermediate shells and having one set of their ends opening to the outside of the casing through the headers, and having the other set of their ends opening to the interior of the casing at opposite ends thereof to provide a retroverted fioW silencer, beads projecting in wardly from the shells to the tubes therein, and apertures formed in one of the shells between the inlet and outlet ends of the tube therein, the beads defining grooves on the outside of the shells.

8. A silencer comprising an outer casing, headers closing the ends thereof, intermediate shells disposed in side by side relation therein, inner tubes within the intermediate shells and having one set of their ends opening to the outside of the casing through the headers, and having the other set of their ends opening to the interior of the casing at opposite ends thereof to provide a retroverted flow silencer, beads projecting inwardly from the shells to the tubes therein, and apertures formed in one of the shells between the inlet and outlet ends of the tube therein, the beads defining grooves on the outside of the shells, one of the beads being adjacent the outlet end of the last mentioned tube and between it and the outlet end of the silencer.

9. A silencer comprising an outer casing, two shells therewithin disposed adjacent each other and side by side and dividing the casing into opposed portions, and beads projecting inwardly from the shells to define grooves therein providing passageways between the opposed portions of the casing, the shells connecting opposed sides of the casing.

FLOYD E. DEREMER. 

